(And, hey, it probably already DOES exist, and I just don't know about it yet.)
The idea is Smart Spam. Imagine you're on your FB page or something, and a window pops up that kinda LOOKS like an IM window. Actually, even more insidiously, maybe it's even disguised as one of your friends. You can have an instant message conversation with this thing that actually resembles a real conversation. The "person" is responding to what you're saying (or at least seems like they are, albeit somewhat distracted or maybe drunk.) At a certain point in the conversation, the person "sells" you on some product, or encourages you to check out some website. Thinking it's your friend, you do. Just got suckered!
The whole time, behind the scenes, it's not a real person at all. It's a piece of software that's programmed to interact with and respond to what you type. A talk bot. Really simple technology that's pretty easy to program. (I even programmed one myself when I was a teenager: http://www.whimnova.com/VI.html)
Okay, there it is. Please don't blame me for it when it starts actually happening.
(Shirks in shame.)